[lwb]

I think that number of classes is the main issue. It's in the many, many millions.

Also, the app has sooooooo much more functionality than people realize. Plus, there is a lot of functionality that ships with the app but is behind a feature gate, meaning that it is turned off for the majority of users. There's lots of internal tools for adjusting feature gates on a per-user, per-region, per-whatever basis, in the name of user research as well as just safely deploying new features at scale.

[munk-a]

Speaking as someone focused on code maintenance this isn't a good thing. If the highest complexity of your product exists at a level where users can't interact with it then you're spending a lot of dev time inefficiently.

But I don't believe you're correct, honestly feature flag rollout, even among insanely specific cohorts, isn't actually a hard problem and it's essentially been solved at this point - it isn't easy, not by any measure - but the components and how they interact are rather easy to comprehend. Facebook's main complexity (IMO) is from trying to build essentially a full OS on top of the browser from which to serve a variety of integration apps into their platform and, while I'm not a board member of Facebook or at all familiar with their earnings, that particular goal seems to have been, essentially, a dud.

Being able to play farmville with your friends may have been a decent income source once upon a time but it's very far from what their core competencies now are. Facebook now primarily uses API hooks into other native standalone apps for that particular class of data collection, but their pure web based collection seems to be where they really get value. The fact that they can see precisely where users are going on the web is, IMO, their main value proposition at this point - the social network stuff needs to exist to support that and ease the process of identifying users - but anything related to games seems utterly unnecessary and that core platform they have could be vastly simplified while still delivering the same value to the company.

That all said, they've invested a whole lot into their existing platform so I can see why business would be very very hesitant to try anything that might rock the boat, if they can sustain their platform being fast and responsive they can minimize their corporate risk.

[traek]

They aren't saying that the feature gating code adds to app size, but rather that there's a lot of code behind feature gates (for tests/staged rollout/locale-specific features/etc) that most users won't see which still add to app size.

[mlcrypto]

Almost as if the user is the product instead of the app. The app is doing everything in the background to monetize the user